JPS6111369A - Method of sealing glass vessel - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of sealing a glass container by heat sealing.

Conventionally, liquid foods (e.g., soft drinks, alcoholic beverages, etc.), pasty foods (e.g., jam, ketchup, mayonnaise, etc.), or powdered foods (e.g., seasonings, etc.) are filled into glass containers, and the mouth of the container is heated. A method of sealing by heat sealing with a plastic resin film is known, but there is a problem in that the adhesive strength of this sealing film decreases over time. This decrease in adhesive strength is particularly noticeable at high temperatures and high humidity, and this is thought to be due to the hydrophilic nature of the glass surface.

Therefore, it has been proposed to use a silane coupling agent as an auxiliary agent, but the silane coupling agent itself has problems with water resistance, and sufficient adhesive strength cannot be obtained by selecting a coupling agent alone. .

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a method for sealing a glass container that provides sufficient adhesive strength and exhibits less strength loss even under high temperature and high humidity conditions. The invention relates to a method for sealing a glass container by heat-sealing the mouth of the glass container with a film-like lid material having at least an adhesive surface coated with thermoplastic resin, which includes applying a metal coating to at least a portion including the mouth of the glass container. The present invention provides a method characterized in that it is formed in advance and then heat-sealed with the lid material.

In the present invention, the metal coating applied to the mouth of the glass container is made of metals other than heavy metals such as lead, and has a relatively small tendency to ionize, such as tin, aluminum, nickel, etc.
Antimony, indium, or an alloy thereof is preferable, and the thickness of the coating is not particularly limited as long as it is uniformly formed on the glass surface, but generally about 1 to 100× is preferable.

The method for forming this metal film on the glass surface is as follows:
After forming the glass container, a metal salt solution or metal alkoxide is sprayed on the glass container at high temperatures until it cools down, or these solutions are completely heated and applied to the glass container, or the hot end is immersed in this heated solution. Treatment method: Alternatively, after forming and cooling a glass container, a metal salt solution or metal alkoxide is applied by spraying, coating, dipping, etc. at room temperature, and then baking (500 to 600°C) or metal oxide is applied. Either mix it with low-melting glass (frit), knead it with oil such as turpentine, apply it, and then bake it (500-600℃), or dissolve the metal resin salt in rosmarin oil or lavender oil and pour it into a glass container. It is possible to adopt a cold-end treatment method in which the material is subjected to heat treatment and then fired.

In addition, a vapor deposition method such as metal snowfall may be employed. The thermoplastic resin applied to the adhesive surface of the lid material should be a resin with good adhesion to the glass container,
For example, ionomers, acid-modified polyolefins, ethylene vinyl acetate copolymers, butyral, polyamides, etc. are preferred. The lid material may be a single layer of thermoplastic resin as described above, or a combination of this and other plastic films.
A laminated film with nonwoven fabric, metal foil, etc. may also be used. When using this laminated film, the thermoplastic resin is naturally applied to the bottom layer (adhesive surface) of the laminated film.

According to the method of the present invention, it is possible to seal various liquid foods, paste foods, powder foods, their fine chemicals, industrial chemicals, etc. in glass containers and store them in a sealed state for a long period of time. . In addition, hot filling of food (temperature 60-95℃)
), and even if steam may be generated from the contents, contaminating the adhesive surface to some extent and forming a water film,
Good heat sealability and strength can be maintained.

Example 1 (1) Tin chloride ethoxide [5nCt2(OC2H5)2
] and (il) ethanol solution (SnO equivalent)
Tin chloride ethoxide and triethoxyantimony [5n
C62(OC2H5)2+5b(OC2H5)3, mixing ratio 1:1] and soda glass (51214, trade name, manufactured by Matsunami Glass Industry ■) respectively.
was immersed for a few seconds, then pulled out, then dried in the air for 15 minutes, and then dried at 120°C for 15 minutes.
As a result, tin and tin/antimony films were respectively formed on the glass.

Next, (a) ionomer (Himilan 1702, trademark, manufactured by Mitsui Polychemical Co., Ltd.) was applied to the At foil (50 μm thick).
, (b) methacrylic acid-modified polyethylene with 5 liters each of Uquerel 714, trademark, and Mitsui Polychemicals (manufactured by Akira).
Coat the cover material film to a thickness of 0 μm and heat 7-
It was adhered to the glass treated with the metal coating described above under the following conditions: 250° C., 3 kg, 7 cm”, and 3 seconds.

The adhesive strength of the resulting lid material is shown in Table 2 below.

For comparison, Table I also shows the adhesive strength when the lid material was adhered under the same conditions without applying a metal coating to the glass surface.

Example 2 16 g of stannous chloride was dissolved in 50 g of ether, added to 45 g of balsam sulfate, and then nitropenzole/
Add lavender oil mixture (mixing ratio 1:6) i, whole 'k
The supernatant liquid was sprayed onto the same glass as in Example 1, and baked at 580° C. for 30 minutes.

Next, using the same lid material as in Example 1, heat sealing was performed under the same conditions as in Example 1, and the adhesive strength thereof was measured.

The results are shown in Table 3 below.

In Examples 1 and 2, almost the same adhesive strength was obtained when polyamide, butyral, or ethylene vinyl acetate≦vinyl copolymer was used instead of the ionomer as the lid material.

Applicant's agent Patent attorney Takehiko Suzue Procedural amendment Showa 9. City, 3(7) Mr. Manabu Shiga, Commissioner of the Patent Office■ Display of terms Patent Application No. 1983-131661 2. Name of the invention How to seal glass containers 3. Person who makes corrections Relationship with patent applicant (319) Toppan Printing Co., Ltd. 11 agents (1? Yuyu's sentence 1 Specification 7. Contents of correction (1) The scope of claims is amended as shown in the attached sheet.

(2) On page 3, line 2 and line 13 of the specification.

In each case, the words "metal film" have been corrected to "metal or metal oxide film."

(3) On page 3, lines 5 and 6, "metal coating" is replaced with "metal for forming a metal or metal oxide coating."
I am corrected.

(4) On page 5, second line from the bottom, "tin and tin/antimony" is corrected to "tin oxide and tin oxide/antimony oxide."

(5) Page 6, line 7 and lines 10 to 1
In the first line, "metal coating treatment" is corrected to "metal oxide coating treatment."

2. Claims (1) A method for sealing a glass container in which the mouth of the glass container is heat-sealed with a film-like lid material having at least an adhesive surface coated with a thermoplastic resin. A film of metal or its oxide is formed in advance on at least the portion containing the metal.

(2) The method according to claim 1, wherein the metal is selected from tin, aluminum, nickel, antimony, indium, or alloys thereof.

Claims (2)

[Claims] (1) In a method for sealing a glass container by heat-sealing the mouth of the glass container with a film-like lid material coated with thermoplastic resin on at least the adhesive surface, a metal coating is applied to at least a portion including the mouth of the glass container. A method characterized by forming the above-mentioned lid material in advance and then heat-sealing it with the lid material. (2) The method according to claim 1, wherein the metal coating is selected from tin, aluminum, nickel, antimony, indium, or an alloy thereof.